Optical Transport Network (OTN) includes a set of Optical Network Elements (ONE) connected by optical fiber links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals. OTN is defined, inter alia, in ITU-T Recommendations G.709 (December/2012) “Interfaces for the Optical Transport Network (OTN),” G.798 (October/2010) “Characteristics of optical transport network hierarchy equipment functional blocks,” G.805 (March/2000) “Generic functional architecture of transport networks,” G.872 (October/2012) “Architecture of optical transport networks,” G.798.1 (April/2011) “Types and characteristics of OTN equipment,” G.7710 (February/2012) “Common equipment management function requirements,” G.7714.1 (April/2003) “Protocol for automatic discovery in SDH and OTN networks,” G.873.1 (July/2011) “OTN Linear Protection,” and G.873.2 (April/2012) “ODUk Shared Ring Protection,” the contents of each are incorporated by reference herein.
Optical (i.e., transport) networks and the like (e.g., wavelength division multiplexing (WDM), Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN), Ethernet, and the like) at various layers are deploying control plane systems and methods. Control plane systems and methods provide automatic allocation of network resources in an end-to-end manner. Exemplary control planes may include Automatically Switched Optical Network (ASON) as defined in G.8080/Y.1304, Architecture for the automatically switched optical network (ASON) (February/2005), the contents of which are herein incorporated by reference; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in Request for Comments (RFC): 3945 (October/2004) and the like, the contents of which are herein incorporated by reference; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical signaling and routing protocol similar to PNNI (Private Network-to-Network Interface) and MPLS; or any other type control plane for controlling network elements at multiple layers, and establishing connections there between. It is essential for the operation of control planes to have control plane signaling and Operations, Administration, Maintenance, and Provisioning (OAM&P) connectivity between nodes.
Clock adjustments in an OTN context can be problematic. For example, when switching from Optical channel Data Unit j (ODUj) to another synchronous or asynchronous source (or vise-versa), a clock transient and frame slip are experienced and alarms are raised unless suppressed by alarm hold-off and conditioning. During this time, OAM&P and control plane signaling is unavailable until recovery is possible. If nothing is done, then user experience spurious alarms when the ODUj service is affected. It has also been determined that these transients can cause cascading glitches in the OTN network. This has been explored in commonly assigned U.S. patent application Ser. No. 13/476,589 filed May 21, 2012 and entitled “OPTICAL TRANSPORT NETWORK TRANSIENT MANAGEMENT SYSTEMS AND METHODS,” the contents of which are incorporated by reference herein. However, conventional solutions only seek to mitigate problems, not eliminate them.